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Researchers in Spain have investigated the potential of using photovoltaic (PV) or photovoltaic-thermal (PVT) systems in microbreweries and have found that PVT systems can cover more energy demand but have a longer payback time.
Researchers from Spains Andalusian Association for Research and Industrial Cooperation (AICIA) have investigated the potential usage of photovoltaic-thermal (PVT) energy for beer brewing. Specifically, they have looked into using PV systems into microbreweries, defined as those with an annual production below 5,000 hectoliters (hl).
“A PVT system has the potential to preheat brewing water and generate electricity,” explained the researchers. “Given the brewing process’s requirement for low-temperature heat and cold, a solar-assisted multi-generation system proves to be suitable. Microbreweries typically lack steam boilers, often relying on gas burners or electric resistors for heat supply. Additionally, small vapor-compression chillers are common for cold production.”
For their investigation, the researcher constructed computational simulations using TRNSYS software, utilizing actual heat and cold load profiles from a Spanish microbrewery located in Jerez de la Frontera, southern Spain. The brewery is assumed to be able to produce 650 l of beer in batches three times per week, totaling an annual production of about 1,000 hl.
“The main energy-related components of the brewery include heat resistors (2 x 10 kW); an air–water chiller 7.5 kW, a chilled water tank 1.3 m3; and an air conditioner-heat pump (ACHP), 3.5/3.2 kW (heat/cold),” the scientists specified.
To deal with the electric and heat loads, several scenarios were created. Firstly, the simulation was run with different panels. It used either 350 W PV modules, 390 W unglazed PVT panels, or 260 W glazed PVT modules. For each of them, three system sizes were considered — 3.9 kW, 10 kW, and 15 kW. They were tested against the climatic conditions of Malaga and Madrid, Spain, and Stuttgart, Germany, along with the relevant economic metrics.
“Furthermore, two configurations of the PVT-plus-thermal storage were analyzed,” added the academics. “The first one considers that the storage tank has an internal coil where the fluid to/from the solar field flows. The working fluid at the storage tank is treated water, since it is an ingredient of the beer, at the temperature of the mains. The second configuration considers that the working fluid at the tank is the same as the one of the solar circuit (water), and through the internal coil flows the treated waters that are later used in the process.”
The simulation showed that the PV-only system could cover between 6.9% and 28.2% of the electricity production in the 4 kW Stuttgart plant and 28.2% in the 15 kW Malaga microbrewery. With the PVT systems, the range was 12.4% to 27.1% in Malaga, 10.4% to 23.9% in Madrid, and 5.8% to 16.9% in Stuttgart.
“When considering just the thermal contribution of the PVT systems for the pre-boiling stage heat demand, between 12% to 47.6% can be covered with the PVT in Malaga, between 11.3% and 42.4% in Madrid, and between 4.9% and 27.6% in Stuttgart,” added the scientists. |
